Prenatal detection of pulmonary hypoplasia in fetuses with congenital diaphragmatic hernia: A systematic review and meta-analysis of diagnostic studies

Abstract

Background. Fetuses with congenital diaphragmatic hernia (CDH) are at risk of death from pulmonary hypoplasia at birth.

Objective. To determine the value of prenatal imaging parameters for predicting lethal pulmonary hypoplasia in fetuses with CDH.

Search strategy. Relevant papers were identified by searching MEDLINE (1966–2008), EMBASE (1988–2008) and the Cochrane Library (2008 issue 3).

Selection criteria. Selected studies examined diagnostic tests for the prenatal prediction of lethal pulmonary hypoplasia in fetuses with CDH. The primary outcome measure was perinatal survival.

Results.  Twenty-one studies fulfilled the entry criteria, of which six examined entirely unique heterogeneous parameters and the remaining 15 examined lung–head ratios (LHR) and/or the presence of liver in the fetal thorax. The strongest association was that of LHR ≥ 0.6 compared to <0.6 (OR: 17.02; 95% CI: 2.10–137.89), although more clinically relevant was that of LHR >1.0 (OR: 5.07; 95% CI: 2.94–8.74). The finding of liver in the fetal chest was a poor prognostic feature (survival OR: 0.32; 95% CI: 0.21–0.49).

Conclusion. In CDH, LHR and the presence of liver in the fetal thorax may be a useful predictive indicator of perinatal survival. Future usage of developing techniques needs careful evaluation prior to usage to guide therapy.

Keywords:

• Congenital diaphragmatic hernia
• pulmonary hypoplasia
• diagnostic test
• ultrasound
• lung–head ratio

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.